Although the original purpose of traffic signals was safety, the adaptive timing of traffic signals by electronic eyes and brains can significantly improve the smoothness of vehicular flow, thereby acting to reduce fuel consumption and emissions, expedite the flow of mass transit and emergency vehicles, save drive time, and reduce wear and tear. In order for the electronic brains to optimize traffic signal timing, electronic eyes must provide adequate information. It has been determined that vehicular presence and velocity are the two necessary ingredients from which all other necessary roadway traffic information can be derived. As a rule, presence sensors do not indicate velocity and velocity sensors are not effective at perceiving stopped vehicular presence. The measurement of the wide range of velocities, i.e., 1-50 mph, the varieties of vehicles, the often erratic flow patterns, the appearance of emergency vehicles and mass transit vehicles, the public environment, weather conditions, and the cost of equipment, installation and upkeep must all be satisfied by the sensor and its operating characteristics. Sensor mounting requirements are often costly and cause traffic disruptions during installation. In the case of overhead arbors, they can be unattractive. If emergency and mass transit vehicles are to be sensed so as to expedite their safe passage, additional sensors are necessary. A single sensor that indicates velocity, presence and special vehicle identification, is convenient to mount, and safely and attractively functions in the increasing complexities of a public environment will serve an important service.